A Cluster-based priority Scheduling Algorithm for MAC Layer in Wireless Sensor Networks

Abstract

Based on the ideas of conflict-free transmission with high-efficiency, cluster-based networking model, and priority service, this article proposes a new scheduling algorithm of MAC protocol of WSNs, which has made possible the polling service capable of differentiating tasks of cluster nodes of two priority levels. The high-priority service of the cluster head is responsible for communication between the different clusters via exhaustive service policy, while the low-priority services of the cluster head node, for communication within the local cluster through limited service policy with good fairness. The theoretical model of this scheme is established through Markov chain, probability generating function, and Laplace-Stieltjes transformation. Mathematical analysis is made on the mean queue length, the mean inquiry cyclic time and the mean delay time. It is found that the findings from theoretical analysis correspond well with those from simulated experiments. The analyses demonstrate that this scheme enables an effective allocation of channel resources for different tasks, guarantee transmission quality of the communication between the different clusters, which further improve the cluster node's energy efficiency.